This invention relates to the accumulation of sheets exiting a printer into a neat stack and then binding the sheets, as by stapling. Apparatus to achieve such function is commonly known as a finisher.
Described herein is an apparatus which receives sheets on a tray and moves the sheets laterally against reference surfaces so as to form a neat stack, which is then stapled or otherwise bound. Because paper and similar sheets buckle and then can move from the forces stored in the buckled sheet, apparatus alternative to that described herein can be cumbersome or unreliable.
The apparatus described herein requires paper or other sheets to fall in a controlled manner on to a tray, such sheets are being fed from a set of rollers and tend to curl forward, which results in the paper not falling flat or not reaching the intended area generally directly under the sheet when fed flat. In accordance with this invention, a mechanism is provided to hold each sheet generally over the tray until the back end of the paper is free, at which point the mechanism frees the sheet to drop downward.
In accordance with this invention a pivoted actuator member is positioned to intersect a printed sheet as it moves out of the printer. The sheet rotates the actuator member. The actuator member has extensions which engage extensions of pivoted bails located on each side of the sheet path. This pivots the bails upward. Each bail has an extended surface, which becomes positioned under the sheet. The sheet is thereby held against curling while the sheet is being exited.
When the sheet has exited and is free, gravity acting on the sheet and the actuator cause the sheet to drop. The bails also drop under gravity.
The sheet is positioned to drop flat and near the exit, as intended for the finisher to form stacks of the sheets.